A 26 year-old man was arrested on Tuesday after a sexual assault in an empty concourse at the Denver National International Airport, which was allegedly witnessed by two airport janitors who did nothing to intervene.

According to the AP, an unidentified 22-year-old woman who missed her connecting flight at the Denver airport on Monday evening subsequently met Noel Alexander Bertrand at an airport restaurant in Concourse A.

The victim says that after the restaurant shut down for the night, Bertrand – a former Marine – followed her into an empty concourse. He attempted to kiss her, and when she refused, he allegedly got violent and raped and assaulted her for approximately 10 minutes.

According to reports, two airport janitors passed by as the rape was occurring, but said nothing and did not step in to stop the assault.

Oregon's Fox 12 News has quoted the victim as saying, "I was appalled that I was going through something so brutal and they kept walking."

Her ordeal continued until two airport employees on the tarmac caught sight of what was happening behind the glass inside the concourse, and called for help. Airport security employees then detained Bertrand until Denver police arrived at the scene.

He remains in custody.

The story has sparked shock and outrage, as many travelers think of airports as some of the most secure, closely-guarded facilities possible.

For travelers stuck overnight at airports, the only option is often to find a quiet area to rest – but an incident like this one might result in added security measures overnight, even in relatively empty gate areas.

Denver's 7News spoke to the victim, who says "It's very important that if you are traveling alone, and you don't have the security of someone with you, that you have the security of the facility that you're in," said the woman. "Especially if it's a government facility like the Denver airport. You should be comfortable being alone. It's hard to say that it was even avoidable. It could have happened to anyone."

7News also received a statement from an airport official who insisted that the airport is indeed safe for women traveling alone: "I would say, absolutely. I don't think this one incident represents the entire airport based off one individual's alleged actions," said Coale. "There are 30,000 people working at the airport. And police did respond."

Officials also confirmed that Denver International will be investigating whether any airport employees witnessed the attack.